(Bug 5073) Tweaks, bugfixes, refactoring

* header-nav mixin has changed name and arguments. Also does a few more
  things, so remove redundant code

* bugfix: "underline" => underline. Strings with quotes around them are
  used as-is. So our CSS ends up having:

     text-decoration: "underline";

  Yuck.
(Bug 5073) Rename header-nav mixin to main-nav

Said mixin includes some code for vertical layouts as well
(Bug 5073) Add skiplinks to foundation in tropo

* use the skiplink components (tt block template, .scss file)
(Bug 5073) Tweak alignment for nav search

* aligns the search form elements with one another
* aligns the search form to match the rest of the top bar
(Bug 5073) Shrinks masthead/logo on tiny screens

Also shrinks the border strip of red in the header on tiny screens
(bug 2566) Auto expand text areas on the Suggest an Improvement page

Auto expands textareas on site/suggest.bml.
Merge pull request #45 from afuna/bug5073-tropo-adjustments

(Bug 5073) Tweaks to tropo (foundation version)
Merge pull request #44 from hotlevel4/bug2566/AutoExpandTextBoxesOnSuggest

(bug 2566) Auto expand text areas on the Suggest an Improvement page
(Bug 5073) Don't use width:100% on #content

The #content element is nested and may have applied margins to it that
could cause scrollbars. So let's use nested-collapse instead of the
default.
(Bug 5073) Remove redundant _skin-colors include

Already included in tropo-base
(Bug 5073) Adds an error section to the top of Foundation pages
(Bug 5073) Add a 1em left margin to all lists
(Bug 5073) Add .row .columns container around page content

This is needed for all pages (to add space around the edge), so add it
to all pages.

Individual pages can still have their own per-section row/column
wrapper.
(Bug 5073) Initial load of pages should have no-js class

Use it to hide elements that require JS to work (class will be changed
after page has loaded)
(Bug 5073) Finish converting Tropospherical Red / Purple
(Bug 5073) Move htdocs/scss/schemes => htdocs/scss/skins
Merge pull request #46 from afuna/foundation-conversion-bug5073

(Bug 5073) Foundation conversion: Tropo skins
(Bug 5073) Add the page-layout-hacks to Tropo

Needs it same as other skins
(Bug 5073) Fix foundation.scss import

htdocs/scss/foundation.scss => htdocs/scss/foundation/foundation.scss
Merge pull request #47 from afuna/foundation-conversion-feedback-bug5073

(Bug 5073) Foundation fixes